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Until an effective vaccine is available, interruption of community circulation of SARS-CoV-2 is crucial to control virus spread. To this end, systematic testing of large population groups by RT-PCR is mandatory to case identification and contact tracing thereby minimizing the likelihood of resurgence in contagion. 1 This approach faces a variety of obstacles, most notably the limited availability of reagents resources. Sample pooling for RT-PCR has been effectively used for screening of blood donors for Human immunodeficiency virus-1 and Hepatitis C virus in lowprevalence setttings. 2 This strategy has also been applied to detect community

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There is limited information on severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) T‐cell immune responses in patients with coronavirus disease 2019 (COVID‐19). Both CD4+ and CD8+ T cells may be instrumental in resolution of and protection from SARS‐CoV‐2 infection. Here, we tested 25 hospitalized patients either with microbiologically documented COVID‐19 (n = 19) or highly suspected of having the disease (n = 6) for presence of SARS‐CoV‐2‐reactive CD69+ expressing interferon‐γ (IFN‐γ) producing CD8+ T cells using flow‐cytometry for intracellular cytokine staining assay. Two sets of overlapping peptides encompassing the SARS‐CoV‐2 Spike glycoprotein N‐terminal 1 to 643 amino acid sequence and the entire sequence of SARS‐CoV‐2 M protein were used simultaneously as antigenic stimulus. Ten patients (40%) had detectable responses, displaying frequencies ranging from 0.15 to 2.7% (median of 0.57 cells/µL; range, 0.43‐9.98 cells/µL). The detection rate of SARS‐CoV‐2‐reactive IFN‐γ CD8+ T cells in patients admitted to intensive care was comparable ( P = .28) to the rate in patients hospitalized in other medical wards. No correlation was found between SARS‐CoV‐2‐reactive IFN‐γ CD8+ T‐cell counts and SARS‐CoV‐2 S‐specific antibody levels. Likewise, no correlation was observed between either SARS‐CoV‐2‐reactive IFN‐γ CD8+ T cells or S‐specific immunoglobulin G‐antibody titers and blood cell count or levels of inflammatory biomarkers. In summary, in this descriptive, preliminary study we showed that SARS‐CoV‐2‐reactive IFN‐γ CD8+ T cells can be detected in a non‐negligible percentage of patients with moderate to severe forms of COVID‐19. Further studies are warranted to determine whether quantitation of these T‐cell subsets may provide prognostic information on the clinical course of COVID‐19.